rs754203594

Positions:

• chr9-98577995-G-A

Variant summary

Our verdict is Benign. Variant got -15 ACMG points: 0P and 15B. BP4_Moderate BP6_Very_Strong BP7 BS2

The NM_005458.8(GABBR2):​c.399C>T​(p.Gly133=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000434 in 1,613,636 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000043 (0 hom.)
• Consequence: GABBR2 NM_005458.8 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 0.0740

Genes affected

GABBR2 (HGNC:4507): (gamma-aminobutyric acid type B receptor subunit 2) The multi-pass membrane protein encoded by this gene belongs to the G-protein coupled receptor 3 family and GABA-B receptor subfamily. The GABA-B receptors inhibit neuronal activity through G protein-coupled second-messenger systems, which regulate the release of neurotransmitters, and the activity of ion channels and adenylyl cyclase. This receptor subunit forms an active heterodimeric complex with GABA-B receptor subunit 1, neither of which is effective on its own. Allelic variants of this gene have been associated with nicotine dependence.[provided by RefSeq, Jan 2010]

ACMG classification

Verdict is Benign. Variant got -15 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.43).
• BP6: Variant 9-98577995-G-A is Benign according to our data. Variant chr9-98577995-G-A is described in ClinVar as [Likely_benign]. Clinvar id is 580388.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.074 with no splicing effect.
• BS2: High AC in GnomAd4 at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GABBR2	NM_005458.8	c.399C>T	p.Gly133=	synonymous_variant	2/19	ENST00000259455.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GABBR2	ENST00000259455.4	c.399C>T	p.Gly133=	synonymous_variant	2/19	1	NM_005458.8	P1
GABBR2	ENST00000637717.1	c.15C>T	p.Gly5=	synonymous_variant	2/3	5
GABBR2	ENST00000634227.1	n.173C>T		non_coding_transcript_exon_variant	2/6	5
GABBR2	ENST00000637410.1	n.177C>T		non_coding_transcript_exon_variant	2/19	5

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152194 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000358 AC: 9 AN: 251414 Hom.: 0 AF XY: 0.0000442 AC XY: 6 AN XY: 135886

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000440

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.0000431 AC: 63 AN: 1461442 Hom.: 0 Cov.: 30 AF XY: 0.0000426 AC XY: 31 AN XY: 727060

Gnomad4 AFR exome AF: 0.0000598

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000504

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152194 Hom.: 0 Cov.: 33 AF XY: 0.0000404 AC XY: 3 AN XY: 74344

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000658 Hom.: 0

Bravo AF: 0.0000529

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Epileptic encephalopathy Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Jan 18, 2024

- -

GABBR2-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Dec 06, 2019

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.43
CADD	Benign	6.9
DANN	Benign	0.81

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs754203594; hg19: chr9-101340277; COSMIC: COSV99410576;